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Sunday, October 16, 2011

blower will not blow air through dash vent on Ford E350?

Many users facing this problem with AC/Blower systems.That Air stops bowing through dash vent.

The problem noticed by others are is as follows :---On the front air it will blow cold or hot but only from the defroster.____________IT WILL BLOW SOMEWHAT HOT AND SOMEWHAT COOL FROM THE DEFROSTER AND FLOOR. NOTHING FROM VENT

In this problem,you will need to do troubleshooting.This problems are not easy to diagnose.It needs time.

Read this description as follows :---

Your main problem with no vent is a air direction motor/solenoid or door broke or binding.
Control Components

The manual climate control components are used to:
select the air inlet source (fresh/recirculated).
select the blower motor speed.
select the discharge air temperature (temperature blend).
select the discharge air location (defrost, panel, or floor).
activate compressor clutch operation.

Control Assemblies

There are four different climate control assembly configurations in the Econoline vehicles:
heater only - standard production
air conditioning and heater
air conditioning and heater (w/ auxiliary air conditioning and heating system)
rear blower control assembly

Control System Inputs

The climate control system inputs are manually selected from the climate control assemblies.

Control System Outputs

The air management doors are controlled by the vacuum control motors (18A318), vacuum control motor, and the A/C electronic door actuator motor (19E616). The air inlet and distribution motors are controlled by the vacuum control motors. The temperature blend door is controlled by the A/C electronic door actuator motor. The temperature control switch position energizes the A/C electronic door actuator motor which provides for a variable number of temperature blend door positions.

The vacuum control motors are used on both the air distribution and air inlet doors. The air inlet and panel door uses a two-position vacuum control motor. The floor duct/panel door uses a three-position vacuum control motor. The vacuum control motors are controlled by engine vacuum through the climate control head.
Distribution Doors

The distribution door positions are determined by the A/C-heater function selector switch. The distribution doors open and close airflow passages inside of the air distribution system to establish airflow direction. There are two distribution doors inside the heater air plenum chamber (18471), the panel/defrost door and the panel/floor door. The panel/defrost door can be positioned to either block off, or direct, air to the panel ducts or defrost ducts. The panel/floor door can either block off, or direct, air to the panel/defrost ducts or the floor duct. The air distribution system is designed to provide defrost when no vacuum is applied to the Floor/Panel vacuum control motor (18A318) and the Floor/Defrost vacuum control motor.

VENT Position

Item

Part Number

Description

1

-

Floor/Defrost Door
(Part of 18471)

2

-

Floor/Panel Door
(Part of 18471)

3

-

Blend Air Door, Max. Warm (Part of 18478)

4

19860

A/C Evaporator Core

5

18504

Blower Motor Wheel

6

-

Outside Air Inlet
(Part of 19B555)

7

01610

Dash Panel

8

-

Blend Air Door, Max. Cool
(Part of 18478)

9

18476

Heater Core

FLOOR Position

DEFROST Position

Your #2 Floor/Panel Door is stuck closed

Remove the floor/panel door vacuum control motor.

Disconnect the vacuum line.

Remove the screws.

Lift the vacuum control motor off the door crank.

Remove the vacuum control motor.

To access the vacuum motor there is a panel on the top of the dash you pry out for access.

check for vacuum when the engine is running and while the knob is turned to vent.

Here is the vacuum diagram from the control head.

Heater and A/C (with or Without Auxiliary Air Conditioning and Heating System)

Vacuum Port and Hose Color

Function (Vacuum Motor)

Function Selector Switch Detent Position

Off

Max A/C

Norm A/C

Vent

Floor

Mix

Defrost

1 - White

Outside/Recirculated

V

V

NV

NV

NV

NV

NV

2 - Red

Full Floor

V

V

V

V

V

NV

NV

3 - Yellow

Panel

V

V

V

V

V

V

NV

4 - Blue

Partial Floor

NV

V

V

V

NV

NV

NV

5 - Black

Source

V

V

V

V

V

V

V

6 -

-

Sealed

.

You need to verify from the door motor to the panel knobs you have no leaks.

If there is a leak just try to run a new line.That's the only option.

This troubleshooting will help you to confirm what is causing the problem.